How Long Are Your Typical Sanding Bars / What Grits Do You Use

[Brendan Eberenz]

I bought a 8ft long piece of 1in squared aluminum. I have tried my 4ft level against it and find that it is nice and flat. I plan on cutting it into varied lengths to create sanding bars. Obviously with 8 ft, I have a lot of options. If you had an arsenal of sanding bars, what sizes would you go with?

I plan to put adhesive backed sandpaper on the bars. Since it is a square bar, I thought I would do one grit on one side and an alternate on the flip side. That way I'm maximizing the utility of my bar. What grits do people prefer to work through as they build?

[Dan Berry]

I only have 12" bars so I'm no help there.
However--- let me recommend that you buy good ( meaning expensive ) sandpaper. Stuff from 3m or some other serious and exorbitant brand.
The difference is astounding and worth the money. Lee Hines turned me onto this years ago while I was building some gliuders.
For gluing it to the bar use 3M Spray 77 or just get a positionable fixatif from the craft store.
I find the self-adhesive paper to be not very adhesive but on a psoitive tick it doesn't sand very well.

[Craig Beswick]

If I had the choices you have I would make the following.
3", 4", 6", 12", 15", 20" and 40"!

I absolutely agree with previous comments, good quality paper is essential! Forget spray on glue just buy stick backed paper.

Nice project. Good luck.

Craig

[Mark wood]

I bought a bunch, like about 5 - 12 foot pieces of 1 1/2" Tee stock at the local Yard Store for $2/lb a couple years ago and I make what ever size I feel is good. I have several in the 5 1/2" and 11" lengths which I generally keep in 80 and 120 grit. I have a few with 220 on them and if I go finer than that, I switch to the dense foam. I've 77M in the past but these days I use double stick carpet tape. The 77m is good but it is a mess and I only need a small amount which means more goes to waist clearing the nozzle than I end up using. The carpet tap is the same size as the bar, goes on easy and hold the sander paper solidly. Removal can occasionally be a trouble but a little heat gun persuasion usually fixes that.

[Dan McEntee]

   You should see what the contoured sanding bars that Great Planes used to put out  go for on eVilBay these days!! WAY more than what you could buy a 6 foot length of T-bar for!!   Some guys just GOTTA have those!! Which I had a bunch to sell !! I use T-bars that I bought or accumulated one way or the other. If I find anything flat I tend to glue sand paper to it. Paint stirring stick, yard stick, pop-cycle sticks, all sorts of stuff.  I also glue sand paper to round stuff and other shapes also. I saw that on a Windy video years ago, and keep all the various shapes in a box. One tool I have that I got the idea from Bob Hunt, and that is a 5 foot long length of aluminum angle with the sharp inside corner like you find at hardware stores. I lined the inside surface of that with sand paper and use that exclusively for edge sanding balsa sheets, and I think I have 100 or 120 grit on that. Another Windy tip was keeping your heavier grit paper separate from you smoother, finer grades so that when grit falls off the heavy stuff it doesn't get stuck on the smoother paper and cause a gouge where you don't want one!! If Kevin King has that Windy video uploaded to the Brownell Channel it is well worth watching.
  Type at you later,
   Dan McEntee

[jerry v]

Brendan,
I hope pictures of my sanding bars and blocks will inspire you and your flying crew to make new models for competition in Brodak, NATS and anywhere else you decide to go!))
Cut only pieces of the length you need now, don’t cut the whole 8 ft aluminum bar in pieces.
Typical self adhesive roll of sandpaper is 2.75 inch wide. It can be cut to cover any length of the bar.
Standard size Wetordry 3M sheet is 9x11 inches. In case of using strips of cut sheet and spray adhesive - the bar should be a bit shorter than 9 or 11 inches.
And nothing is better (flatter) than piece of 1/2 inch or 3/4 inch thick glass…

Jerry.

[Dave Harmon]

I use the Great Planes 12" and longer bars.
I like the 3M yellow 150 grit for shaping and 3M 220.
Get this paper on rolls from automotive paint stores.
A roll lasts for a looong time.
It is sticky back but if the sanding bar ls cleaned with lacquer thinner it works well although I have used 3M77 occasionally.
I also have a 18x36 steel surface plate that I put down a length of 150 grit and it makes sanding leading edges and 3/8 solid elevators and flaps a 15 minute job....accurately too!

[Brendan Eberenz]

Hey folks, thanks for the responses and insight. I cut a 12in bar last night and threw 120grit on one side and 220 on the other. I am happy with the results and even used it to notch a few perfectly square corners into a project I am working on.